1. Field of the invention
The present invention relates to a miniature air pump with an innovative structure, and more particularly, to a miniature air pump which can optionally choose the number of air bladders, and improve pump structure so as to stabilize the air output of the pump.
2. Description of the Prior Art
A conventional miniature air pump can only produce compressed air, and perform air intake and output function with a defined air chamber. Such a simply constructed miniature air pump often causes an unsmooth air flow due to its inherent shortcomings in the structural design.
For example, a well known conventional electronic sphy gmomanometer in the world requires installation of an outer check valve to refuse back flow of high pressure air into the pump so as to prevent measurement error.
It is an object of the present invention to provide a miniature air pump which can optionally choose the number of air chambers, and improve pump structure and function.
It is another object of the present invention to provide a miniature air pump which can be formed into a compact size and many pleasant contours for customers free choice.
It is still another object of the present invention to provide a miniature air pump whose bladders are able to sequentially output pressurized air from an air output hole after introducing the air into the pump via an air pathway, and also able to prevent the back flow of air with a membrane functioning as a check valve.
These and other objects of the miniature air pump according to the present invention comprises a motor unit, a compression unit, and an air collection unit.
Wherein, the motor unit further includes a main motor portion, a base, and a rotor portion. A rotating shaft which being extended out of the main motor portion tunnels through the base and is coupled with the rotor portion whereat an eccentric hole is provided. Several air inlet apertures are formed at the side of the base.
The compression unit further includes a compression vane, a fixture, and several compression chambers. A follower rod which being extended out of the center of the compression vane is inserted into the eccentric hole formed on the rotor portion with a predetermined offset angle. The compression chamber is composed of a bladder, a flow check membrane, and a leak proof gasket. Each compression chamber is conjoined with the compression vane by a tenon formed at the rear of each bladder mated with a corresponding mortise eye formed on the compression vane after tunneling through the fixture. A first check valve is installed on the fixture facing to the flow check membrane for each compression chamber.
The air collection unit has several flow pathways corresponding to the bladders, several membranes functioning as second check valves are equipped at each exit side of the flow pathway, several guide slots each formed between the first check valve and the bladder, and an air output port is formed at the topmost end thereof.